/* ----------------------------------------------------------------------
 * Project:      CMSIS DSP Library
 * Title:        arm_q15_to_q31.c
 * Description:  Converts the elements of the Q15 vector to Q31 vector
 *
 * $Date:        18. March 2019
 * $Revision:    V1.6.0
 *
 * Target Processor: Cortex-M cores
 * -------------------------------------------------------------------- */
/*
 * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "arm_math.h"

/**
  @ingroup groupSupport
 */

/**
  @addtogroup q15_to_x
  @{
 */

/**
  @brief         Converts the elements of the Q15 vector to Q31 vector.
  @param[in]     pSrc       points to the Q15 input vector
  @param[out]    pDst       points to the Q31 output vector
  @param[in]     blockSize  number of samples in each vector
  @return        none

  @par           Details
                   The equation used for the conversion process is:
  <pre>
      pDst[n] = (q31_t) pSrc[n] << 16;   0 <= n < blockSize.
  </pre>
 */
#if defined(ARM_MATH_MVEI)
void arm_q15_to_q31(
	const q15_t *pSrc,
	q31_t *pDst,
	uint32_t blockSize)
{

	uint32_t blkCnt;

	q31x4_t         vecDst;

	blkCnt = blockSize >> 2;
	while (blkCnt > 0U) {

		/* C = (q31_t)A << 16 */
		/* convert from q15 to q31 and then store the results in the destination buffer */
		/* load q15 + 32-bit widening */
		vecDst = vldrhq_s32((q15_t const *) pSrc);
		vecDst = vshlq_n(vecDst, 16);
		vstrwq_s32(pDst, vecDst);

		/*
		 * Decrement the blockSize loop counter
		 * Advance vector source and destination pointers
		 */
		pDst += 4;
		pSrc += 4;
		blkCnt --;
	}

	blkCnt = blockSize & 3;
	while (blkCnt > 0U) {
		/* C = (q31_t) A << 16 */

		/* Convert from q15 to q31 and store result in destination buffer */
		*pDst++ = (q31_t) * pSrc++ << 16;

		/* Decrement loop counter */
		blkCnt--;
	}
}
#else
void arm_q15_to_q31(
	const q15_t *pSrc,
	q31_t *pDst,
	uint32_t blockSize)
{
	uint32_t blkCnt;                               /* Loop counter */
	const q15_t *pIn = pSrc;                             /* Source pointer */

#if defined (ARM_MATH_LOOPUNROLL)
	q31_t in1, in2;
	q31_t out1, out2, out3, out4;
#endif

#if defined (ARM_MATH_LOOPUNROLL)

	/* Loop unrolling: Compute 4 outputs at a time */
	blkCnt = blockSize >> 2U;

	while (blkCnt > 0U) {
		/* C = (q31_t)A << 16 */

		/* Convert from q15 to q31 and store result in destination buffer */
		in1 = read_q15x2_ia((q15_t **) &pIn);
		in2 = read_q15x2_ia((q15_t **) &pIn);

#ifndef ARM_MATH_BIG_ENDIAN

		/* extract lower 16 bits to 32 bit result */
		out1 = in1 << 16U;
		/* extract upper 16 bits to 32 bit result */
		out2 = in1 & 0xFFFF0000;
		/* extract lower 16 bits to 32 bit result */
		out3 = in2 << 16U;
		/* extract upper 16 bits to 32 bit result */
		out4 = in2 & 0xFFFF0000;

#else

		/* extract upper 16 bits to 32 bit result */
		out1 = in1 & 0xFFFF0000;
		/* extract lower 16 bits to 32 bit result */
		out2 = in1 << 16U;
		/* extract upper 16 bits to 32 bit result */
		out3 = in2 & 0xFFFF0000;
		/* extract lower 16 bits to 32 bit result */
		out4 = in2 << 16U;

#endif /* #ifndef ARM_MATH_BIG_ENDIAN */

		*pDst++ = out1;
		*pDst++ = out2;
		*pDst++ = out3;
		*pDst++ = out4;

		/* Decrement loop counter */
		blkCnt--;
	}

	/* Loop unrolling: Compute remaining outputs */
	blkCnt = blockSize % 0x4U;

#else

	/* Initialize blkCnt with number of samples */
	blkCnt = blockSize;

#endif /* #if defined (ARM_MATH_LOOPUNROLL) */

	while (blkCnt > 0U) {
		/* C = (q31_t) A << 16 */

		/* Convert from q15 to q31 and store result in destination buffer */
		*pDst++ = (q31_t) * pIn++ << 16;

		/* Decrement loop counter */
		blkCnt--;
	}

}
#endif /* defined(ARM_MATH_MVEI) */

/**
  @} end of q15_to_x group
 */
